1. Field of the Invention
The invention relates to a method and a device for recording/reproducing digital broadcasting signals of a program and in particular, to a method and a device which can perform time-shift reproducing (delayed reproducing) of the program.
2. Description of the Related Art
An analog VTR (Video Tape Recorder) has been spread to record broadcasting signals of a program. When the VTR records broadcasting signals of the program, the VTR receives the broadcasting signals from a broadcasting station via an antenna, and transforms the received signals into predetermined form of signals for recording. And then, the VTR records the transformed signals on a magnetic tape using a magnetic head. Such the processes are well known in the public
Also, after the VTR records broadcasting signals of a program in response to an instruction of a user, the VTR can again display the recorded signals of the program on a television set, by rewinding the tape and reproducing the signals of the program.
In such the VTR, it is impossible to record image data and sound data of the program to a magnetic tape and reproduce the data from the magnetic tape, simultaneously. For example, the VTR can not record a program which starts at 8:00 p.m. and ends at 10:00 p.m. while reproduction of the program is started at 9:00 p.m. from the beginning of the program. Furthermore, the VTR can not receive and record a program while performing special reproduction such as fast-forward reproduction of the recorded signals of the program.
In this regard, a conventional delay reproducing apparatus is disclosed in Japanese Laid Open Publication No. H07-336253(namely, 336253/1995). The conventional delay reproducing apparatus stores signals of a program to a RAM (random access memory) or a magnetic tape to pretend that broadcasting of the program is paused for a predetermined duration. Thus, in the apparatus, when a user starts watching a program, which is broadcast from 8:00 p.m. to 10:00 p.m., at 9:00 p.m. from the beginning of the program, the recording of the program is started at 8:00 p.m. and the reproducing of the recorded signals of the program is started at 9:00 p.m. The reproducing of the recorded signals of the program can be started at a timing an hour later than a timing when broadcasting of the program is actually started by continuing the recording of signals of the program to the RAM or an endless tape.
However, in the conventional apparatus, although data of a program can be reproduced at a timing delayed by a predetermined duration from an actual broadcasting time of the program, the delayed duration is limited to a very short time due to a small capacity of the RAM or the endless magnetic tape.
Also, recently, a DVR (Digital Video Recorder) has been known which can record data of a TV program (contents) to a HDD (hard disk drive). The DVR can “rewind” and reproduce a missed signals (image data or sound data) which are broadcast in several seconds before, while data of a program being recorded. This function is referred to as “time-shift reproduction”.
The DVR is, for example, disclosed in a Japanese magazine “NIKKEI Pasokon” published in Jan. 24, 2000, page 28.
But, the DVR disclosed in the above magazine can not complete reproduction of a program at almost the same timing as an end time of real broadcasting of the program, even if the reproduction is started a long time behind the starting of the real broadcasting of the program.
Also, the magazine does not disclose a method of preventing a file from destruction when a power of the DVR is suddenly shut down during the DVR records signals of the program and a method of recording a full-length program to a small amount of storage medium. Therefore, the magazine does not disclose a specific effective configuration of the DVR at all.